Injector



H4 DEUTSCH Feb 7, QBQ,

INJEGTOR Filed March 7, 1958 Patented F eb. 7, 1939 UNITED STATES PATENTOFFICE INJECTOR Application March 7, 1938, Serial No. 194,457 In AustriaJanuary 22, 1938 4 Claims.

My invention relates to injectors of the kind in which the closure ofthe overflow valve is automatically controlled by means of a piston. Itis necessary in an arrangementof this kind in order .3 to secureimmediate restarting of the injector after a sudden interruption of thewater-supply, that the mechanism ensuring closure of the overiiow valveduring the feeding operation of the injector immediately allows freemovement of the lo overow valve, when the water-supply is momentarilyinterrupted.

My invention, therefore, provides a multipart piston With stepped partsof different diameter for the control or" the overflow valve with two ormore parts of different diameter working within a stepped cylinder room.One of said parts is acted upon by the pressure of the live steamadmitted to the injector, while another part of said piston is exposedto the pressure which prevails in the delivery chamber or in thedelivery pipe of said injector. Whenever the injector fails momentarilyon account of an interruption in the water supply, the live steamadmitted to the cylinder in which the piston is housed will cause astroke of the stepped piston and will -thus allow free movement of theoverflow valve. Conversely the presence of pressure in the deliverychamber of the injector causes a movement of the multipart piston whichthrough an intermediate lever will effectively secure closure of theoverflow valve.

A further feature of the invention consists in means for retarding theclosure of the overiiow valve, when the injector starts feeding. Forthis purpose a non-return valve is inserted into the pipe leading liveor working steam to the stepped cylinder room and opening towards thisroom. Moreover, one part of the multipart piston is inserted into thecorresponding part of the cylinder room with a certain clearance. Thefluid mixture in the stepped cylinder by virtue of the non-return valvewhich prevents its escape towards the admission pipe acts as a brakewhen pressure is applied to the piston from the delivery chamber onstarting as this uid mixture can only escape very slowly through theclearance between the piston and the surrounding cylinder. Thus, themovement f the piston which on starting and restarting leads to therelease of the overflow Valve is retarded and the steam filling theoverflow chamber before the formation of the jet has sufcient time toescape into the open air. Easy starting and restarting without failureis thus secured.

According to a further modication of the ln- (Cl. 10B- 275) vention thepiston consists of three parts of diierent diameters, with alongitudinal bore in one of said parts and a transversal bore leadinginto the cylinder room in another part communicating with each other.The longitudinal bore leads 5 to a part of the cylinder connected withthe live or working steam admitted to the injector, and this bore isclosed by a non-return valve opening towards the transversal bore. Themiddle part of the cylinder room is connected with the 10 deliverychamber of the injector as already described.

In this modiiication all the elements necessary for the above describedoperation are contained within the housing of the multipart piston andl5 the arrangement may therefore be added to an existing injectorwithout modification of the same and without difficulty.

The invention is illustrated in the accompanying drawing which showsseveral modications 20 of the same. Figs. 1 and 2 show an injectoraccording to the invention in vertical section and in cross sectionrespectively. Figs. 3, 3a and 4 show two further modiications or theinvention. In all gures similar parts are designated 25 by similarreference letters.

In the modification of the injector shown in Figs. 1 and 2, the casing'l of the injector contains the steam nozzle 2, the combining nozzle 3and the delivery nozzle 4. By means of the pipe 5 30 feed-water issupplied to the injector and through the channel S and over thecheck-valve 'l the water to be fed into the boiler is delivered into thepipe 8 leading thereto. A cylinder bore l0 is in connection with thedelivery chamber 9 of the 35 injector, which has an extension I Icoaxial therewith, but of smaller diameter. A stepped piston consistingof two parts of diierent diameter is sliding Within the bores l and I l.The larger part I2 of the piston is housed in the bore I 0, 40 while asmaller rod like part I3 passes through the bore l I and projects to theoutside. Between the part I2 of said piston and the bore ill a clearanceor a small annular space is left so that the mixture of steam and waterenclosed within the 45 cylinder room IB will slowly escape through saidclearance if the piston is moved upwardly. The rod like part I3 of thepiston is guided in a stuiiing box M. The part projecting to the outsidewill come into contact with the two-armed lever l5 50 and l5r1l whichmay rock around an axle I6 and which controls the overow-valve. When therod like part I3 of the piston presses the end I5 of said leverupwardly, the other end I5a of the lever will come into contact with thevalve stem 55 Il of the overow valve I8 (Fig..2) and will hold it closedforcibly.

In the position shown in Figs. 1 and 2' the lever I5, Ia. however isentirely clear of the overflow valve I8, which is thus released and mayfreely move. The stepped piston I2, I3 is in this case in its lowermostposition as the injector is not working.

From the cylinder room Ill which houses part I2 of the piston a channelI9 leads to a chamber 2i) which in its turn is connected by means of achannel Zita to a point 29h of the injector 50 which the live or workingsteam of the injector is admitted. A ball shaped non-return valve 2I isarranged in said chamber 253 which opens in the direction towards thecylinder room It.

The operation of this arrangement is the following:

When the inject r is started the live or working steam under pressureadmitted to the injector will also enter at point 2th the channel Ztaand will flow through the chamber 29 into the cylinder room Hl, so thatpressure will be exerted upon the upper surface of part I2 of thestepped piston. The piston is, therefore, pressed downwardly and theoverflow valve in this case is released and may freely move as it is nolonger held by the lever I5, i501. The uid mixture which is formed inthe nozzles may thus freely escape to the open air by entering theoverflow chamber and passing the overflow valve. As soon as pressurebegins to build up in the delivery chamber 9 such pressure istransmitted to the lower surface of the piston part I2 and overcomes thepressure on the upper surface of said part, as the lower surface islarger than the upper surface, the difference in the area being due tothe fact that the lower surface is fully utilized while on the uppersurface the part I3 of the piston will diminish the exposed area of thesurface.

.Thus, the pressure acting on the upper surface is overcome and thepiston I2, I3 is pressed upwardly; the part I3 of the piston will thenlift the end I5 of the two-armed lever I5, I5a andy will close theoverflow valve forcibly.

If, however, the injector fails momentarily, say on account of a suddeninterruption of the water supply or from any other cause, the pressurein the delivery chamber 5 is lowered so that it is lower than thepressure of the live or working steam admitted to the injector whichprevails in the cylinder room Iii and acts on the upper surface of thepiston I2. In this case the multipart piston I2, I3 is moved downwardly,the overflow Valve I8 is released and the uid mixture consisting ofsteam and water which has entered from the inner parts of the injectorinto the overflow chamber may escape freely into the open air. When theinjector restarts high pressure is again building up in the deliverychamber 9. The stepped multipart piston I2, I3 is therefore again pushedupwardly. The iluid mixture enclosed in the cylinder room It above thepiston I2 and which is prevented from ilowing back by the nonreturnvalve 2i acts as a cushion and is retarding the movement, as it can onlyescape through the small annular clearance between the piston I2 and thebore of the cylinder room I8 into the delivery chamber 9. The closing ofthe overflow valve I8 is thereby retarded in such a manner thatthe steamentering the overflow chamber during the period which is necessary toestablish an active jet in the injector has ample time to escape intothe open air by means of the overflow valve I8.

In the modiiicaticn shown in Fig. 3 the stepped multipart piston I2, I3is directly connected with the delivery check-valve 'I of the injectorin such a manner that lifting of the stepped multipart piston at thestarting of the injector can only take place simultaneously with thelifting of the pressure valve l. Likewise the return movements of thesetwo members can only be performed in common. For this purpose the lowerface of the piston I2 is provided with a projection or extension 22which is embraced by a suitably formed part 23 of the valve I so thatthe stepped multipart piston i2, I3 and the valve 'I may only be movedin common. The rest of the arrangement is exactly the same as thatdescribed with reference to Figs. l and 2. Also the operation of thismodication corresponds to that already described'with reference to Fig.1.

In the modication shown in Fig. 3 the piston I2, I3 forms one piece andthe delivery check valve I is connected with it in the manner described.However, as shown in Fig. 3a. also the delivery check valve 'I and thepart I2 of the piston might form one piece connected with the part I3 ofthe piston in the same manner as the delivery check valve 'l isconnected with the part I2 of the piston in Fig; 3. The delivery checkvalve i is then provided with a projection carrying a head I2 whichconstitutes one part of the multipart piston and which is provided witha forklike extension on top corresponding to part 23 in 3 and embracingthe lower end of the part I3 ofthe piston corresponding to the extension22.

In the modification of the invention shown in Fig. 4 the steppedmultipart piston I2, I3 which is moving with a certain clearance betweenit and the cylinder room 28 into the latter is provided with a thirdpart or extension ZlI of a smaller diameter than that of the upper rodlike part I3 of the stepped piston. This extension 24 slides in a bore25 coaxial with the bore I and the stuffing box Ill. Thus, a steppedthree roomed cylinder houses a piston consisting of three parts ofunequal diameter. A small branch of the live or working steam admittedto the injector is conveyed into the cylinder bore 25 by means of thechannel or pipe Iii which leads to the cylinder room 25. The extension2li reciprocating in said room is provided with an axial bore 26 whichleads into a transversal bore 21 provided in the part I3 of the piston,a non-return-valve 2l being inserted at the mouth of the bore 25. Thus,the live or working steam admitted to the injector is also admitted tothe cylinder bore Ill where it can act on lthe upper surface of the partI2 of the piston. The cylinder bore 28 which is located below the pistonI2 is connected with the delivery chamber 9 of the injector by means ofa pipe 29.

All the various other parts are similar to'those described and shownwith reference to Figs, 1

and 2. i

This modification of the invention has the advantage that all partsnecessary for controlling the closure and the release of theoverflow-valve are assembled in the housing of the piston and thearrangement may therefore be very easily added to an existing injector,thus allowing a marked improvement of injectors already in use.

The operation of the modification is the following:

When the injector is started the live steam admitted to the injectorflows through pipe I9 and bore 25, lifts the non-return valve ZI andenters into the channel 21 so that the cylinder room 'lil Iabovepart I2of the piston is filled with steam under pressure. The piston I2 is inthis case pressed downwardly. Thereby the overflow valve will bereleased. The iiuid mixture contained in the overflow chamber may nowreadily escape into the open air. However, as soon as pressure has builtup in the delivery chamber 9 of the injector iiuid under pressure willalso enter pipe 29 and cylinder chamber 28 located below the piston i2.

As the part I3 of the piston is of a larger diameter than the extension2d at the lower part of the pistonl the stepped multipart piston 211,I2, i3 moves upwardly and closes the overow valve i8 and secures closureof said valve during the working of the injector. During such start-`ing or restarting operation of the injector the iiuid mixture of steamand water which is enclosed in the cylinder room lil above the part l2of the piston and which is prevented from escaping by the non-returnvalve 2i will act as a retardation means and will slow down the movementof the stepped multipart piston 2d, l2, i3. This iiuid mixture can onlyescape through the small annular clearance between the part i2 of thepiston and the cylinder room lil into the cylinder chamber 28. Theeffect is the same as that described in connection with the modicationshown in Figs. l and 2. lThe closing of the overiiow valve I8 will thusbe retarded so that there is ample time for an efcient feeding jet tobuild up within the injector. Steam entering into the overilow chamberduring this period may escape freely whereby the starting or restartingis greatly facilitated.

What I claim is:

l. An injector comprising a delivery chamber, an overflow valve and aseat therefor, a piston with one part exposed to the pressure in thedelivery chamber and with another part projecting to the outside, asystem of levers acted upon by said outwardly projecting part of thepiston and capable of either forcing the overflow valve upon its seat orof allowing free play thereof, said piston being formed as a steppedpiston with a large surface acted upon by the pressure of the waterdelivered from the injector and a small annular surface acted upon bythe working steam of the injector, the pressure of the water in thedelivery chamber thus acting by means of said piston, its outwardlyprojecting end and the lever system on the overflow valve of theinjector and forcing it upon its seat, while in the absence of pressurein the delivery chamber the pressure of the Working steam acting onanother surface of the piston will move the same away from the leversystem, free play of the overiiow valve being thus allowed.

2. An injector comprising a delivery chamber,

an overflow valve and a seat therefor, a piston with one part exposed tothe pressure in the delivery chamber of the injector and with anotherpart projecting to the outside, a system of levers acted upon by saidoutwardly projecting part ci the piston, and capable of either forcingthe overflow valve upon its seat or of allowing free play oi the same, acylinder, said piston being formed as a stepped piston with a largerportion moving in said cylinder with a certain clearance, and a smallerannular suriace acted upon by the working steam of the injector, a pipeleading said working steam to the cylinder and being provided with acheck valve opening towards the cylinder.

3. An injector comprising a delivery chamber, an overiiow valve and aseat therefor, a piston with one part exposed to the pressure in thedelivery chamber of the injector and with another part projecting to theoutside, a system of levers acted upon by said outwardly projecting partof the piston and capable of either forcing 'the overflow valve of theinjector upon its seat or of allowing free play of the same, said pistonbeing formed as a stepped piston, with a large surface acted upon by thepressure of the water delivered from the injector and a small annularsuriace acted upon by the working steam of the injector, the action ofsaid working steam moving the piston away from said lever system andallowing free play of the overow valve in the absence of pressure in thedelivery chamber, a delivery check valve cooperating with said pistonwhereby the latter moves with the piston.

fl. An injector comprising a delivery chamber, an overow valve and aseat therefor, a piston with one part exposed to the pressure in thedelivery chamber of the injector and with another part projecting to theoutside, a system of levers, acted upon by said outwardly projectingpart of the piston and capable of either forcing the overflow valve ofthe injector upon its seat or or" allowing free play of the same, acylinder, said piston including cylinders, three stepped parts ofdifferent diameter, the iirst part having the smallest diameter workingin one of said cylinders communicating with the working steam chamber ofthe injector, the second part with the largest diameter moving withinanother of said cylinders with a certain clearance, the third partprojecting to the outside, the rst part of the piston having alongitudinal bore and the third part of the piston having a transversebore communicating with said longitudinal bore and a check valve closingsaid longitudinal bore.

HANS DEUTSCH.

